Patents by Inventor Alfred I. Pan

Alfred I. Pan has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5408738
    Abstract: In one of the preferred embodiments, an inkjet printhead includes a nozzle member formed of a polymer material that has been laser-ablated to form inkjet orifices, ink channels, and vaporization chambers in the unitary nozzle member. The nozzle member is then mounted to a substrate containing heating elements associated with each orifice. In a preferred method, the orifices, ink channels, and vaporization chambers are formed using an Excimer laser.
    Type: Grant
    Filed: October 18, 1993
    Date of Patent: April 25, 1995
    Assignee: Hewlett-Packard Company
    Inventors: Christopher A. Schantz, Eric G. Hanson, Si-Ty Lam, Paul H. McClelland, William J. Lloyd, Laurie S. Mittelstadt, Alfred I. Pan
  • Patent number: 5350616
    Abstract: A composite orifice plate for a printer such as a thermal inkjet printer includes a first layer of non-wettable material and a second layer of wettable material joined to the first layer. In the orifice plate, at least one orifice is formed to extend through the first layer and at least one opening is formed to extend through the second layer, the orifice and opening are in fluid communication and aligned in an axial direction with an ink outlet located on a surface of the first layer facing away from the second layer and an ink inlet located on a surface of the second layer facing away from the first layer.
    Type: Grant
    Filed: June 16, 1993
    Date of Patent: September 27, 1994
    Assignee: Hewlett-Packard Company
    Inventors: Alfred I. Pan, Ellen R. Tappon
  • Patent number: 5291226
    Abstract: In one of the preferred embodiments, an inkjet printhead includes a nozzle member formed of a polymer material that has been laser-ablated to form inkjet orifices, ink channels, and vaporization chambers in the unitary nozzle member. The nozzle member is then mounted to a substrate containing heating elements associated with each orifice. In a preferred method, the orifices, ink channels, and vaporization chambers are formed using an Excimer laser.
    Type: Grant
    Filed: April 2, 1992
    Date of Patent: March 1, 1994
    Assignee: Hewlett-Packard Company
    Inventors: Christopher A. Schantz, Eric G. Hanson, Si-Ty Lam, Paul H. McClelland, William J. Lloyd, Laurie S. Mittelstadt, Alfred I. Pan
  • Patent number: 5121132
    Abstract: An ink delivery system for an inkjet printer includes a vented supply chamber for providing a reservoir of ink and an ink compartment which is connected to the supply chamber via a hydrophobic membrane which acts as a fluid diode for regulating the flow of ink from the supply chamber into the compartment.
    Type: Grant
    Filed: February 28, 1991
    Date of Patent: June 9, 1992
    Assignee: Hewlett-Packard Company
    Inventors: Alfred I. Pan, C. S. Chan, Conrad L. Wright
  • Patent number: 5113199
    Abstract: A system for delivering ink to print heads in thermal ink jet printers includes a liquid compartment with a gas space thereabove at sub-atmospheric pressure, a hydrophobic membrane mounted between the liquid compartment and the surrounding environment for allowing ambient gases to bubble into the liquid while preventing liquid from flowing in the opposite direction through the membrane, at least one chamber that provides a reservoir of ink with a gas space thereabove at sub-atmospheric pressure, and a manifold connecting the gas space in the liquid compartment with the gas space in the ink chamber. Thermal ink jet print heads are mounted in ink-flow communication with the ink chamber and are adapted for ejecting ink onto sheets to be printed. In operation, ink flows into the thermal ink jet print heads at a flow rate which is regulated by a generally constant back pressure.
    Type: Grant
    Filed: March 11, 1991
    Date of Patent: May 12, 1992
    Assignee: Hewlett-Packard Company
    Inventors: C. S. Chan, Alfred I. Pan
  • Patent number: 4965611
    Abstract: Disclosed is an improved thermal ink jet print head with an amorphous diffusion barrier that inhibits corrosion associated with ink. The head has a silicon substrate, a silicon dioxide insulating layer, a tantalum aluminum alloy (TaAl) resistive layer, and two separated gold conductive regions formed over the resistive layer. Ink is drawn into a channel bounded above by an orifice plate and below by the TaAl exposed between the two separated gold regions. The ink is superheated and expelled as fine droplets through the orifice plate. The invention minimizes corrosion by placing a thin corrosion-resistant layer of amorphous metallic alloy over the conductive layer, thereby improving durability of the print head.
    Type: Grant
    Filed: March 22, 1989
    Date of Patent: October 23, 1990
    Assignee: Hewlett-Packard Company
    Inventors: Alfred I. Pan, Eric G. Hanson
  • Patent number: 4931813
    Abstract: A thermal ink jet head incorporates bubble-generating resistors, each with a relatively thick layer of unpassivated resistive material, such as TaAl. The thermal ink jet head includes an ink source, ink channels, respective orifices, and circuitry for providing the electrical energy which the resistors convert to heat to form bubbles which expel ink through respective orifices. A range between 3,000 .ANG. and 5,000 .ANG. is preferred for the resistive material to minimize failure rate while avoiding thermal, electrical and manufacturing limitations of passivated resistors.
    Type: Grant
    Filed: February 28, 1989
    Date of Patent: June 5, 1990
    Assignee: Hewlett-Packard Company
    Inventors: Alfred I. Pan, Howard H. Taub, Harold W. Levie
  • Patent number: 4417947
    Abstract: The edge profile of a silicon layer is shaped to have a gradual incline considerably less than 90.degree. by continuously reducing the amount of oxygen mixed with carbon tetrachloride in a reactive ion etching environment. The etching mode varies from complete isotropic etching when the amount of oxygen is maximum, to complete anisotropic etching when the oxygen content is zero.
    Type: Grant
    Filed: July 16, 1982
    Date of Patent: November 29, 1983
    Assignee: Signetics Corporation
    Inventor: Alfred I. Pan